JP5060481B2 - Capacitor and method resistant to heat-induced damage - Google Patents

Description

  This application claims priority to US Provisional Patent Application No. 60 / 595,783 filed Aug. 5, 2005, which is hereby incorporated by reference and is attached. Attached as A.

Many existing capacitors are made using a capacitor body with a metallized film. The metallized film typically has a thin polymer film, such as polypropylene, on which the thin metal film is condensed or deposited. The metallized film is arranged so that a thin metal film forms two separate internal electrodes separated by a polymer film. Two separate internal electrodes are substantially electrically isolated from each other, and capacitance is shown between the internal electrodes. The thin metal film of each internal electrode is connected to the end electrode, and the terminations are connected to each end electrode to electrically connect to the capacitor.

  In some cases, two separate sheets of metallized film are rolled or wound together with a cylindrical capacitor body having two generally circular ends. The sheets of metallized film are offset from each other so that each separate sheet extends only to one of the generally circular ends. In such a case, each end electrode is positioned at one of the generally circular ends and is connected to a sheet of metallized film that extends to the end where the end electrode is positioned. This structure results in an annular capacitor having a cross-section with a layer of metallized film alternating between two separate internal electrodes formed by a thin metal film on each sheet. In this case, each of the end electrodes is connected to a layer of the respective internal electrode.

  In other cases, each of the internal electrodes is formed with a separate layer of metal deposited film to create a rectangular capacitor body. In such a case, one internal electrode layer is arranged to alternate with the other internal electrode layer and is offset from the other on the two ends. The end electrode in such a case provides an electrical connection between the individual layers of each internal electrode at the offset end. Other types of capacitors have dielectric and metal layers, such as polymers that are not affixed to one another prior to capacitor assembly, in various tail configurations.

  One common technique used to make end electrodes is a molten end spray metal (molten) that can have tin, zinc, or other conductors in this technique, referred to as end spray. end spray metal) is sprayed onto each of the offset ends of the layer of metallized film. Spraying continues until the end spray metal accumulates to a constant thickness. The end spray metal sticks to the metal vapor deposition film, and when the molten metal cools and solidifies, the end spray metal is electrically connected to the metal of the metal vapor deposition film. The solidified end spray metal on each end connects to one of the internal electrodes that serves as the end electrode. Typically, the end spray metal is sprayed onto the end of the metallized film as uniformly as possible. Other techniques for making metal end electrodes may also be usable.

  One problem with the use of metal or other types of rigid end electrodes involves capacitor failure due to cracking of one or both of the end electrodes. Many crack problems are thermally induced as a result of capacitors undergoing temperature changes and repeated temperature cycles. In some cases, the thermally induced crack has a condition in which one or both end electrodes are at least partially separated from the internal electrode of the capacitor body. Such isolation changes the characteristics of the capacitor, such as capacitance and / or conduction or other characteristics of the capacitor. Other types of heat-induced cracks or damage include cracks where the end electrodes themselves shatter.

  Capacitor operation in a wide temperature environment exacerbates the problem of heat-induced cracking. In environments with multiple types of tests, capacitors are placed at temperatures ranging from −50 ° C. to 100 ° C. When the capacitor is heated under the influence of the outside and / or inside, the layer and the end electrode of the capacitor expand, and when the capacitor is cooled, the end electrode and the end electrode contract.

  In many cases, cracks are a direct result of a dielectric having a CTE that differs from the coefficient of thermal expansion (CTE) of the edge. In some cases, the CTE of the dielectric is on the order of greater than the CTE of the end electrodes. When the dielectric CTE is greater than the end electrode CTE, the dielectric expands at a faster rate than the end electrode. Thereby, the internal electrode surrounded by the dielectric can be separated from the end electrode.

  A typical capacitor receives heat generated outside the capacitor as well as inside the capacitor. External heating is typically provided by a device and air surrounding the capacitor that provides approximately uniform heating of the capacitor. On the other hand, internal self-heating is caused by electrical losses inside the capacitor. Internal self-heating may cause the metallized film or other internal electrodes and dielectric ends to be exposed to higher temperatures than the electrodes. This situation causes a more rapid failure of the capacitor as the metallized film expands further than the end electrode due to the elevated temperature encountered by the metallized film, and thus typically damages the end electrode or to the capacitor Cause other damage.

  In some cases, different parts inside the capacitor will be hotter than other parts inside the capacitor. In such a case, the metallized film expands further in the hotter than the colder parts, resulting in non-uniform stress on the end electrodes that can lead to capacitor failure.

  The rigid end electrodes of multiple capacitors can be quite large, sometimes exceeding 10 inches in diameter or more for cylindrical capacitors. Such large capacitors have many layers with dielectric materials that expand together to increase the overall dimensions in one or more directions of the capacitor when heated. The overall expansion of each dimension of the dielectric is greater than the overall expansion of each corresponding dimension of the rigid end electrode. Thus, the end electrode has a crack because the dielectric and the rigid end electrode are connected to each other and the dielectric expands faster than the end electrode. Although heat-induced cracks occur in small capacitors and large capacitors, heat-induced cracks can also occur in large capacitors.

The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will be apparent to those skilled in the art with reference to the specification and drawings.
US Pat. No. 6,477,035 B1 specification US Pat. No. 6,829,133 B2

  The present invention relates, at least in part, to a segmented end electrode capacitor and a method for segmenting an end electrode of a capacitor.

  The following examples and aspects thereof are described and illustrated in connection with systems, tools, and methods that are intended to be exemplary and illustrative rather than limiting in scope. In various embodiments, one or more of the problems described above are reduced or eliminated, while other embodiments are directed to other improvements.

  A method of manufacturing a capacitor is described in this disclosure. The method allows the capacitor to withstand heat-induced damage. In the method, the capacitor is formed by using a dielectric material between the first conductive layer and the second conductive layer and positioning the first conductive layer spaced from the second conductive layer. Is done. The first layer has a first layer longitudinal edge at the first end of the capacitor body, and the second layer has a first edge at the second opposite end of the capacitor body. It has two layers of longitudinal edges. The end spray metal is sprayed into the contact with the longitudinal edge of the first layer at the first end of the capacitor body (An end spray metal is sprayed with the first). layer lengthwise edge) and is also sprayed into contact with the longitudinal edge of the second layer at the second end of the capacitor body to create a second end electrode. End spray metal has a coefficient of thermal expansion different from that of the dielectric material. The first end electrode is divided into first electrode segments that are each electrically connected to different portions of the longitudinal edge of the first layer at the first end. The first electrode segment is positioned to thermally expand and contract the dielectric material, while the segment continues to be electrically connected to different portions of the longitudinal edge at the first end. The first electrode segments together have a flexible conductor to electrically connect the first electrode segments together while moving the first electrode segments substantially independently of each other. Connected. The capacitor exhibits an capacitance between the connected first electrode segment and the second end electrode.

  Another method disclosed relates to a method for reducing thermally induced damage in metal deposited film capacitors. The capacitor has an arrangement of first and second internal electrodes made with a layer of metallized film that is electrically isolated from each other. The first internal electrode is electrically connected to the first end electrode at the first end, and the second internal electrode is connected to the second end electrode at the second end Electrically connected. The first and second end electrodes are substantially rigid and have a coefficient of thermal expansion different from that of the metal vapor deposited film. The end electrode is divided into electrode segments to thermally expand and contract into the metal vapor deposition film, while the first internal electrode continues to be electrically connected to the first end electrode, The two internal electrodes continue to be electrically connected to the second end electrode.

  Another method involves manufacturing a capacitor having a metal end electrode connected to a wound metal deposited film. The metal deposited film has a dielectric that expands and contracts thermally. The end electrode is divided into a plurality of electrode segments that can move substantially independently of each other while still connected to a metallized film that responds to thermal expansion and contraction. Is done.

  The disclosed capacitor has a first conductive layer having a first layer longitudinal edge and a second conductive layer having a second layer longitudinal edge, the first and second conductive layers. The layers are spaced apart from one another. The dielectric material is positioned between the first conductive layer and the second conductive layer. The first end electrode is electrically connected to the longitudinal edge of the first layer, the second end electrode is electrically connected to the longitudinal edge of the second layer. The The second end electrode is divided into a plurality of electrode segments each connected to a different portion of the longitudinal edge of the second layer. The dielectric material can be thermally expanded and contracted while the electrode segments are still connected to the longitudinal edges of the second layer. The capacitor exhibits a capacitance between each of the electrode segments and the first electrode.

  In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and the following description.

  A capacitor 20 according to the present invention is shown in FIG. A typical capacitor 20 has a capacitor body 22 and two end electrodes 24 and 26 that are divided into end segments 28 and 30, respectively. By dividing or segmenting the end electrodes 24 and 26, the segments can move substantially independently of each other, avoiding or reducing the occurrence of thermally induced cracks in the end electrodes.

  Each of the segments 28 and 30 is connected to a different part of the capacitor body 22 and has a rigid interface and is not directly connected to each other. This allows the individual segments 28 and 30 to move with the expansion and contraction of the portion of the capacitor body 22 that is connected without causing cracks in the end electrodes 24 and 26.

  Since each segment is connected to a different part of the capacitor body, each segment is substantially only subjected to forces caused by the connected part of the capacitor body. The force is caused by a relative change in dimensions between the segment and the portion of the capacitor body to which it is attached, since the segment and the capacitor body have different coefficients of thermal expansion (CTE). By splitting the end electrodes into segments, such forces are overcome by the mounting strength between the capacitor body and the segments.

  The segment has a segment edge 32 and a segment face (face) 34 as in FIGS. In multiple cases, as shown in FIGS. 1 and 2, the segment edges 32 of adjacent segments at least temporarily contact each other. This is unlikely to affect the substantially independent nature of the segment motion relative to each other. The gap 36 defines a segment edge 32 between adjacent segments. In other cases, segment edges 32 of adjacent segments 28 or 30 do not contact each other at any temperature as shown in FIG. In such a case, the gap 36 is relatively large. Other partially extending gaps 39, as in FIG. 1, are not between separate electrode segments, but instead may extend only partially across the electrode segments. The partially extending gap 39 may cause the electrode segment to deform rather than crack when subjected to stress. Other structures of gaps and segments can also be used to reduce the occurrence of heat-induced damage.

  As the capacitor temperature rises, the segments move further away from each other. In such a case, the segments move further away from each other because the material in the capacitor body 22 has a higher CTE than the material of the end electrodes 24 and 26 has. This situation results in an increase in the size of the gap 36 between adjacent segments and also limits or eliminates the effect that the movement of one segment has on the movement of the other segment. Thus, as capacitor body 22 rises in temperature, it expands at a faster rate than segments 28 and 30, and the segments are moved away from each other in the plane of end electrodes 24 and 26.

  The carrier band body 22 has internal electrodes or conductive layers 38 and 40 and dielectric material or layers 42 and 44 as shown in FIGS. Conductive layers 38 and 40 are arranged to generate capacitance. The capacitor body 22 shown in FIG. 1 has a cylindrical or annular shape with two circular ends to which end electrodes 24 and 26 are connected to conductive layers 38 and 40, respectively. In this example, the capacitor body 22 defines a cylindrical opening 45.

  In some cases, the cylindrical or annular shaped capacitor body 22 has generally circular end electrodes 24 and 26 defined by a radius 47 extending from a center point 49. A circular gap 37 may be used with the capacitor body 22, the circular gap being defined by a radius 51 that extends from the center point 53. In this case, the center point 53 may be positioned at a different position than the center point 49, and the circular gap 37 is generally not concentric with the circular end electrode 24. Due to the non-concentric nature of the circular gap 37, for a substantial length that limits the distance that current must flow along the length of the conductive layer 38 or 40 before reaching the end electrodes 24 and 26, The gap is generally not collinear with the conductive layer 38 or 40.

  In the case of the cylindrical capacitor body 22 of this example, the body is formed by rolling together two sheets 46 and 48 having a metal deposited film. The metal deposition films 46 and 48 have film portions that serve as dielectrics 42 and 44, respectively, and the metal layer deposits a thin coating on the film portions and serves as conductive layers 38 and 40, respectively. . Typically, the film portion is a type of polymer and the metal is deposited on the polymer by corresponding metal deposition. Multiple layers with conductive layers 38 or 40 and dielectrics 42 and 44 are shown in the cross section of the cylindrical body 22 as shown in FIGS. 2 and 3, while every other layer 38 or 40 is simple. Shows additional turns (turns) of the sheets 46 and 48, respectively. As shown in FIGS. 2 and 3, the capacitor body 22 increases its radius in the direction of arrow 54.

  The two sheets 46 and 48 are rolled together to form the capacitor body 22 in this example, with the conductive layer 38 extending against the longitudinal edge 50 of the sheet 46, as shown in FIGS. The conductive layer 40 extends relative to the longitudinal edge 52 of the sheet 48. Conductive layer 38 is connected to segment 28 of end electrode 24 along longitudinal edge 50.

  Other methods of configuring the capacitor body 22 into a cylindrical shape or other shape can also be used. For example, separate layers and dielectrics with conductive material can be used and the capacitor body can be formed with a rectangle.

  End electrodes 24 and 26 are typically attached to capacitor body 22 by spraying end spray metal onto longitudinal edges 50 and 52, respectively. In this spraying process, the end spray metal is heated to the molten state of the metal, and metal droplets are deposited onto the edges 50 and 52, making contact with the conductive layers 38 and 40, respectively. Metals used for end spray metals include tin, zinc, and / or others. End spray metal droplets are deposited on the capacitor body 22 until the end electrodes are sufficiently thick. In some examples, sufficient thickness means that the end electrode can withstand the connection of the flexible conductor 56 (FIG. 3) at the connection point 58 on the face 34 of the end electrodes 24 and 26. Sure. As an example, the thickness of the sprayed electrode in the plurality of capacitors is typically between 0.005 "and 0.025".

  In some cases, the end electrodes 24 and 26 are segmented or divided by using a mask having a spraying process (by using a mask with the spraying process). In such a case, the mask is placed against the longitudinal edges 50 and 52 of the capacitor body 22 during the spray process. The mask can have metal rods or spokes. The metal rod or spoke prevents the droplet end spray metal from reaching the portions of the longitudinal edges 50 and 52 of the conductive layers 38 and 40 that leave the gap 36 at the end electrodes 24 and 26. Segments 28 and 30 are formed with an end spray metal where the mask does not prevent droplet contact with the longitudinal edges 50 and 52. Other materials and masking techniques can be used to make end electrodes 24 and 26 having segments 28 and 30.

  Segments 28 and 30 are also made by sawing or cutting the end electrodes 24 and 26 after the end electrodes are connected or formed on the capacitor body 22 as a rigid or undivided portion. Can be. In one example, a circular saw blade is used to cut the gap 36 at the end electrodes 24 and 26 to create the segments 28 and 30. The plurality of segments 28 and 30 are split with at least a plurality of gaps 36 disposed along the radius of the circular end electrode. Other segment patterns or arrangements can also be used as long as the segments reduce the occurrence of end electrode cracks. Multiple segment patterns or arrangements may be superior in reducing or eliminating heat-induced damage compared to other segment patterns or arrangements. This may depend, at least in part, on the direction in which the capacitor body 22 expands maximally when heated. A person skilled in the art will be able to achieve appropriate segmentation under this application using masks, sawing, or other suitable methods or the like.

  The number of segments is based at least in part on the dimensions of the end electrodes 24 and 26 in the plurality of cases. Larger end electrodes generally require more segments than smaller end electrodes. Typically, more segments result in a reduced risk of heat-induced damage than fewer segments for a given dimension of the electrode. However, since it is typically more difficult to attach the flexible conductor 56 to a smaller segment, there is a practical limit to the number of segments from which the end electrode can be divided. As an example, a cylindrical or annular capacitor having electrodes having a diameter of about 10 inches may have 12 to 24 separate electrode segments on each end. These and other end electrodes may have more or fewer segments, and the arrangement or number of segments on each end electrode of a single capacitor may vary.

  The segments 28 and 30 shown in FIG. 3 have a flexible conductor 56 and are attached to the buses 60 and 62. Buses 60 and 62 are relatively rigid and flexible conductors 56, as shown in FIG. 3, and bendable metal that allows the segments to move relative to each other without leaving buses 60 and 62. Made with Flexible conductor 56 electrically connects segment 28 to bus 60 and electrically connects segment 30 to bus 62. The buses 60 and 62 serve as terminals so as to connect the capacitor 20 to other electrical components (not shown).

  As shown in FIG. 4, the flexible conductor 56 is made with a braided wire. The flexible conductor 56 in this case electrically connects the adjacent segments 30 to each other at the connection point 58 and the adjacent segments 28 to each other. In this arrangement, all segments 28 are electrically connected to each other to serve as end electrodes 24 and all segments 30 are to each other to serve as end electrodes 26. Electrically connected. The flexible cables 64 and 66 serve as terminals so as to electrically connect the end electrodes 24 and 26 of the capacitor 30 to other electric parts.

  Additionally or alternatively, each of the segments 28 and 30 may each have an independent flexible terminal so that all segments are electrically connected and / or the segments are electrically Grouped together in groups. In multiple cases, the terminals are connected together externally to the capacitor. In multiple cases, the capacitor may have only one end electrode that is divided into segments. In general, the connection to segments 28 and 30 should have a flexible nature that does not unduly interfere with the movement of one segment relative to the other segment.

  A further advantage of connecting an independent flexible terminal for each of the segments is that the equivalent series inductance (ESL) of the capacitor is compared to a similar capacitor that does not have an independent terminal for each segment. Be reduced. ESL reduction is important because it improves the performance of the circuit to reduce ripple on the power bus. As each segment has a separate terminal and is connected to the power bus, each segment operates as a quasi-discrete capacitor. This reduces the overall ESL of the capacitor relative to the same capacitor having a single continuous end electrode with a single terminal on each end of the capacitor. So that

  Segmenting one or more end electrodes improves the reliability of the capacitor by reducing or eliminating the failure or degradation of the capacitor due to heat-induced damage. The effect of CTE mismatch is mitigated by the splitting of the end electrodes into segments that reduce the forces that serve to damage the end electrodes. The segment reduces or eliminates the effect that a portion of the expanding portion of the capacitor has on a segment that is not connected to that portion of the capacitor body. By segmenting the end electrodes, the segments can move in different directions and / or at different speeds, reducing stress between different portions of the end electrodes. Segmented end electrodes can be used on capacitors having a metal or rigid interface between the capacitor internal electrode layer and external connections.

  By way of overview, the present application, as one exemplary embodiment, segments capacitors with segmented end electrodes and capacitor end electrodes to reduce or eliminate the occurrence of thermally induced damage to the capacitors. A method is disclosed.

  While several exemplary aspects and embodiments have been described above, those skilled in the art will recognize certain modifications, substitutions, additions, and sub-combinations. Accordingly, the appended claims are intended to be construed as including all such modifications, substitutions, additions, and subcombinations within the spirit and scope of this application.

  In the following, the contents of US Provisional Patent Application No. 60 / 595,783, to which this application claims priority, as described at the beginning will be described.

  <Attachment A (U.S. Provisional Patent Application No. 60 / 595,783)>

<Document Name> Claims <Claim 1>
A method of making an electrical connection to two terminals of a rolled metallized film capacitor that is suitable for use in a wide temperature range of applications, wherein a plurality of sprayed sprays formed on each end of the capacitor body Metal electrode segments, and each electrode segment on each end of the capacitor body is electrically connected to an adjacent electrode segment on the same end of the capacitor body by a conductive element that is mechanically compliant. The gap between adjacent electrode segments is sufficient to prevent inter-segment interference over a wide temperature range.
<Claim 2>
A method of making an electrical connection to two terminals of a metallized film wound to achieve a low equivalent series inductance, wherein a plurality of sprayed metal electrode segments formed on each end of the capacitor body include: And each of the plurality of electrode segments at each end of the capacitor body is electrically connected to a common electrode by a conductive element that is mechanically compliant.

<Document Name> Description <Title of Invention> Power Ring Capacitor Segmented End Spray <Technical Field>
The present invention relates to a method for electrically connecting to a metallized film capacitor to increase reliability over a wide temperature range and to reduce the equivalent series inductance of the capacitor.

<Background technology>
The present invention describes a design concept that results in a capacitor with the following performance that has not been recognized by the applicant to be available on the market as of June 28, 2005. For large diameter metallized film capacitors, there is a significant temperature coefficient mismatch between the end spray metal and the metallized film. This can be a major problem when the capacitor is operated over a wide temperature range. As the temperature increases, the film expands further than the metal end spray expands. Temperature coefficient mismatch is a more serious problem with internal self-heating because the internal temperature is higher than the end spray metal. This refers to further expansion of the film against the cooler end spray that occurs when the capacitor temperature is purely an effect of ambient temperature.

<Disclosure of invention>
<Problem to be solved by the invention>
The present application alleviates the effect of this discrepancy by moving the end spray into sections or segments, and the absolute value of the relative motion between the film and the end spray is seen when a continuous metal end spray is used. Deal with methods that will be greatly reduced compared to discrepancies. This improvement results in a more reliable capacitor because the stress in contact between the end spray metal and the capacitor film is greatly reduced as the capacitor temperature moves above or below the end spray process temperature. .

<Means for solving the problem>
Metal deposited capacitor structures are known in the art. The metallized film is wound on a roll and each film layer extends against one side of the rolled section. Connections to metal deposition are made by spraying molten metal droplets on each end of the capacitor and making it thick enough to attach electrical terminations.

  With mask, saw cut, or other means to create a pattern that divides the end spray area at the end of the capacitor winding into discontinuous or nearly discontinuous islands or segments It is proposed to design a capacitor end spray system. Over the operating temperature range, this segmentation limits the absolute discrepancy that occurs at a given location for some value that depends on the size and shape selected for the segment. The pattern can be anything that achieves this goal, and the appropriate number of segments or partial segments can be used. Each end spray segment is connected to the other segment so that the connection does not have significant additional mechanical stress on the film capacitor windings and can be deflated and contracted. The capacitor may have multiple terminations for the load, having a terminal for each end spray segment, without limitation. Interconnection between adjacent sections can be made through external means such as, but not limited to, braided wires, bent or folded metal strips, or independent electrical ends for each segment or group. Interconnection between the segments is then made external to the capacitor.

  The segment pattern design can meet the needs described above. This segmentation process can be used in capacitors with a connection through a sprayed metal interface between the capacitor internal electrode layer and the external connection.

  The process of segmenting this capacitor end connection has not been recognized by the applicant as available on the market as of June 28, 2005.

<Best Mode for Carrying Out the Invention>
The segmented end spray metal described above is shown in FIGS. FIG. 1 is a schematic diagram of a rolled metallized film capacitor known in the art. The capacitor has multiple turns of a thin polymer film, such as polypropylene, with a thin metal film previously deposited and patterned. The electrical contact to the alternating layers of the rolled cylinder is made at the end of the cylinder by using a metal coating that is typically sprayed onto the two end surfaces of the cylinder, and the close electrical Contact is made between the individual metal film layers of the winding and the end electrodes. The two end sprayed electrodes form the electrical terminals of the finished capacitor. Normally, the end spray is deposited as evenly as possible onto the end of the cylinder.

  FIG. 2 is an illustration of the disclosed method of forming the two ends of a wound film capacitor. The capacitor in this case has a diameter larger than its thickness and a hollow central region, resulting in a ring-shaped device. End spray electrodes are deposited on the two large flat surfaces of the cylinder. Each electrode is patterned into a plurality of smaller electrode segments. The segments on one side of the cylinder are electrically connected to each other to form a single capacitor end. The segments on the other side of the cylinder are similarly connected to each other. The mechanical association between segments is minimized to reduce the mechanical strength between segments. This allows individual segments to mechanically shift relative to each other without improper mechanical stress on the underlying rolled cylinder.

  Another aspect of the disclosed invention is a reduction in equivalent series inductance (ESL) that can be achieved with segmented electrodes. When large ripple voltages have to be reduced in power buses with the appropriate physical range, the preferred method is to electrically connect a plurality of individually connected parallel and physically distributed along the power bus. It is known in the art to include the use of capacitors. This reduces the ESL of the complete circuit and improves the performance of the circuit to reduce voltage ripple on the power bus. The individually disclosed segmented end electrodes provide the same function. Each segment has a separate lead connected between it and the power bus. The leads are selected to provide minimal mechanical stress on the electrode segments, especially when the device is temperature cycled. Each segment operates as a quasi-discrete capacitor, and the overall ESL of the segmented electrode capacitor is the same with a single continuous end electrode and a single electrical lead on each end of the capacitor. Compared to that of the capacitor.

  One advantage of the present invention is that it minimizes as much mechanical stress as possible due to the mismatched temperature coefficient between the end spray electrode and the wound cylinder body of the capacitor. Another advantage of the present invention is that the relative motion of the end spray and capacitor section is minimized with segmentation, allowing the best reliability in applications where a wide range of temperature cycles is a typical environment. To do.

  Another advantage of the present invention is that if the capacitor is manufactured with an end remote from each segment (or subgroup of segments), the capacitor is currently manufactured without using the disclosed end spray segmentation. It can perform optimally with very low ESL in bus bypass and / or energy storage applications, with performance that exceeds the ESL of the capacitor.

<Brief description of drawings>
FIG. 1 illustrates a prior art wound metal deposited polymer film capacitor structure.
FIG. 2 illustrates a segmented end spray electrode.

＜図２＞

<Document name> Drawing <Figure 1>

<Figure 2>

<Document Name> Summary <Summary> A method of patterning a sprayed metal end connection to a wound metal deposited film capacitor is described. The patterned end connection improves capacitor reliability over a wide operating temperature range and reduces the equivalent series inductance of the capacitor.

FIG. 6 is a perspective view of a capacitor having end electrodes segmented in accordance with the present disclosure. FIG. 2 is a cross-sectional view of the capacitor along a cutting line 2-2 in FIG. 1. FIG. 6 is another cross-sectional view of a capacitor according to the present disclosure having segmented end electrodes that are electrically connected to each other. 1 is a perspective view of a capacitor according to the present disclosure having segmented end electrodes that are electrically connected to each other. FIG.

Claims (34)

A method of manufacturing a capacitor that is resistant to heat-induced damage, comprising:
The first conductive layer having a longitudinal edge of the first layer at a first end of the capacitor body by positioning the first conductive layer spaced from the second conductive layer; Forming a dielectric material between the second conductive layer having a longitudinal edge of a second layer at a second opposing end of the capacitor body;
A coefficient of thermal expansion different from that of the dielectric material to contact the longitudinal edge of the first layer at the first end of the capacitor body to form a first end electrode; Spraying the end spray metal with the end spray metal in contact with a longitudinal edge of the second layer at the second end of the capacitor body to create a second end electrode. Spraying; and
Dividing the first end electrode into first electrode segments that are each electrically connected to different portions of the first layer at a longitudinal edge of the first layer at the first end; ;
The first electrode segment is a flexible conductor so that the first electrode segments can move substantially independently of each other while electrically connecting the first electrode segments together; Having and connecting together,
Have
The first electrode segment is arranged to thermally expand and contract the dielectric material, while the segment continues to the different portions of the longitudinal edge at the first end. Each of the first electrode segments of the first end electrode is adapted to move as the dielectric material expands and contracts thermally;
The capacitor, indicates the capacitance between the connected first electrode segments and the second end electrode,
The gap between the first electrode segments in close proximity has a radial and circular gap,
Method. Dividing the second end electrode into second electrode segments;
The second electrode segment is made of a flexible conductor so that the second electrode segments can move substantially independently of each other while electrically connecting the second electrode segments together; Having and connecting together,
Further comprising
The second electrode segments are each electrically connected to different portions of the longitudinal edge of the second layer at the second end so that the dielectric material can thermally expand and contract. While still connected to the longitudinal edge of the second layer,
The capacitor, indicates the capacitance between said connected second electrode segments the connection to the first electrode segment,
The gap between the immediately adjacent second electrode segments has a radial and circular gap,
The method of claim 1. A metal-deposited polymer film is used in the step of forming the conductive layer and the dielectric.
The method of claim 1. The first end electrode is divided into first electrode segments by sawing and cutting the first end electrode;
The method of claim 1. The first end electrode masks the first end of the capacitor body before spraying the end spray metal to contact the longitudinal edge of the first layer. Divided into one electrode segment,
The method of claim 1. The first end is masked with a metal mask having a metal rod;
The method of claim 5. The end electrode is divided using a cutter tip,
The method of claim 1. The first end electrode has a generally circular shape defined by a first radius extending from a first center point, and the first electrode segment extends from a second center point. has a segment circular shape defined by a second radius of standing, the first and second center point, different locations near is, the gap of the circular shape between the first electrode adjacent segments directly, At the second radius,
The method of claim 1. A method for reducing heat-induced damage in a metallized film capacitor, the capacitor comprising an arrangement of first and second internal electrodes made with layers of a metallized film that are electrically isolated from each other The first internal electrode is electrically connected to the first end electrode at the first end, and the second internal electrode is the second end at the second end. Electrically connected to an end electrode, wherein the first and second end electrodes are substantially rigid and have a coefficient of thermal expansion different from that of the metallized film;
The method is:
Dividing the end electrode into electrode segments;
Have
The dividing step allows the metal deposited film to be thermally expanded and contracted, while the first internal electrode is still electrically connected to the first end electrode, and the second The internal electrode continues to be electrically connected to the second end electrode;
Each of the electrode segments of the end electrode is adapted to move as the metallized film thermally expands and contracts;
The gap between the immediately adjacent electrode segments of each end electrode has a radial and circular gap,
Method. The end electrode is divided into segments by sawing and cutting the end electrode after the end electrode is sprayed onto the internal electrode in a dissolved state.
The method of claim 9. The end electrode is divided into electrode segments by masking the end of the internal electrode and spraying the end electrode into contact with the internal electrode on the end.
The method of claim 9. The segment is masked with a metal mask having metal rods;
The method of claim 11. The end electrode is divided using a cutter tip,
The method of claim 9. Electrically connecting the electrode segments at one end to each other and electrically connecting the electrode segments at the other end to each other, wherein the electrode segment at the one end is the electrode at the other end Electrically isolated from the segment,
The method of claim 9. The metal deposited film is arranged in alternating layers by rolling the metal deposited film into a generally cylindrical shape.
The method of claim 9. A method of making a capacitor having a metal end electrode connected to a rolled metallized film having a dielectric that thermally expands and contracts:
Dividing each of the end electrodes into a plurality of electrode segments;
Have
The plurality of electrode segments can move substantially independently of one another while being connected to the metallized film in response to thermal expansion and contraction;
Each of the plurality of electrode segments of the end electrode is adapted to move as the dielectric material thermally expands and contracts;
The gap between the immediately adjacent electrode segments of each end electrode has a radial and circular gap,
Method. Further comprising electrically connecting the electrode segments of each end electrode to one another with one or more flexible electrical connectors;
The method of claim 16. The electrode segments are electrically connected to each other using one or more braided cable electrical connectors;
The method of claim 16. The end electrode is divided using a cutter tip,
The method of claim 16. The metal end electrode has a generally circular shape defined by a first radius extending from a first center point, and the electrode segment has a second end extending from a second center point. has a segment circular shape defined by a radius of said first and second center point, different locations near is, the gap of the circular shape between electrode segments adjacent direct the metal end electrodes, the At the second radius,
The method of claim 16. Capacitor:
A first conductive layer having a longitudinal edge of the first layer;
A second conductive layer having a longitudinal edge of the second layer;
A dielectric material positioned between the first conductive layer and the second conductive layer;
A first end electrode electrically connected to the longitudinal edge of the first layer;
A second end electrode electrically connected to the longitudinal edge of the second layer;
Have
The first and second conductive layers are spaced apart from each other;
The second end electrode is divided into a plurality of electrode segments each connected to a different portion of the longitudinal edge of the second layer, and the dielectric material expands and contracts thermally. While the electrode segment continues to be connected to the longitudinal edge of the second layer, and the capacitor exhibits a capacitance between each of the electrode segments and the first electrode;
Each of the plurality of electrode segments of the second end electrode is adapted to move as the dielectric material thermally expands and contracts;
The gap between the plurality of electrode segments of the second end electrode has a radial and circular gap,
Capacitor. The electrode segment is a second electrode segment, and the first end electrode is divided into a plurality of first electrode segments each connected to a different portion of the longitudinal edge of the first layer. The dielectric material can be thermally expanded and contracted while the second electrode segment continues to be connected to the longitudinal edge of the first layer and the first end The gap between the electrode segments of the electrode has a radial and circular gap,
The capacitor according to claim 21. The first and second conductive layers are each part of a single sheet having a metallized polymer that is generally rolled into a cylindrical shape.
The capacitor according to claim 21. The second end electrode has a generally circular shape, and the electrode segment is defined by a gap positioned at least partially over the radius of the circular shape.
The capacitor according to claim 23. The second end electrode has a generally circular shape, and the number of electrode segments is based on the radius of the circular shape;
The capacitor according to claim 23. The circular shape of the second end electrode has a diameter of about 10 inches and the number of electrode segments ranges from 12 to 24;
The capacitor according to claim 25. The number of electrode segments is based on the dimensions of the second end electrode,
The capacitor according to claim 21. The electrode segments are divided to optimize resistance to heat-induced cracking of the second end electrode;
The capacitor according to claim 21. At least two of the electrode segments have flexible conductors connected together;
The capacitor according to claim 21. The flexible conductor is a braided wire,
30. The capacitor of claim 29. The flexible conductor is a flexible metal strip;
30. The capacitor of claim 29. Each of the electrode segments is connected to a separate electrical terminal;
The capacitor according to claim 21. The second end electrode has a generally circular shape defined by a first radius extending from a first center point, and the electrode segment extends from a second center point. has a segment circular shape defined by a second radius, said first and second center point, different locations near is, a circular shape between the electrode segments to direct proximity of the second end electrode The gap is at the second radius,
The capacitor according to claim 21. At least one particular electrode segment has a gap that extends partially across said particular electrode segment;
The capacitor according to claim 21.

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